SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3b92add95fcecd2047d7fb5b79a1d7b6d49a76269d8f5ca6a98d32f55dc9d87' 
  AND token = '0oovAo4YCDU7hofvgLZlvO9UrFIUo4MZD0aycqhdHNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}